The study, published in Proceedings of the National Academy of Sciences, is the first systemic mapping of brain lesions associated with criminal behavior, a medical phenomena referred to as acquired sociopathy.
Darby did the research during a fellowship at Harvard Medical School. Famous cases of acquired sociopathy include Phineas Gage, a railroad worker who in 1848 exhibited anti-social behavior after surviving an explosive blast that sent an iron rod through his brain, and Charles Whitman, the “Texas Tower Sniper,” who had a brain tumor and murdered 16 people in 1966.
Darby and co-authors reviewed more recent cases of brain lesions associated with criminal behavior, examining MRI and CT scans of those individuals. One group of 17 cases had a definitive correlation between criminal behavior and a brain lesion. A second group of 23 cases had an implied correlation when researchers didn’t know whether the brain lesion occurred before or after the criminal behavior. In both groups, the lesions were at different areas of the brain.
The researchers used neuroimaging analyses — large datasets compiled from healthy volunteers organized into a connectome, similar to a map of brain activity. While the lesions were in different brain areas, they were all connected to the same brain network.